Sorry if it feels as if I'm attacking you, but I've seen that rather baseless argument a lot from the anti crowd.
I am for it, and have been. I still feel (rather strongly), if SGR couldn't be in, OGR shouldn't have been. But that's me. I get that is a common "excuse", "justification", "reason", etc. of the anti crowd. For me, I have a(n) attachment to Andros & Gault. The other companions are okay, just those two are my favorite. I also get it puts those who have progressed or completed the class stories in a bad spot (I'm pretty sure others like them, too). And it wouldn't be fair to those to have to replay. Which is why I'm sure someone will feel short changed. Not sure how that will go, just get it doesn't mean I'm against it.
Andros, whose name I shorten from Andronikus Revel is a companion of the Sith Inquisitor. Gault, is a companion of the Bounty Hunter. I am sure romancing them would be fun, for a lot of reasons. However, that's not the relationship they have with the BH & SI am currently playing. I have played two of every class. I'm all down for a romance the second time. This one? It'll ruin it. I'm in the early stages of Act 3 currently. Maybe I'm off, but I'd feel by now they would have made a pass at me (or vice versa). As it stands, it'll feel forced, and I'd rather have it done right. But yeah, that's just my opinion on it.